1161320161 has 4 divisors (see below), whose sum is σ = 1162288324. Its totient is φ = 1160352000.

The previous prime is 1161320123. The next prime is 1161320177. The reversal of 1161320161 is 1610231611.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 508773136 + 652547025 = 22556^2 + 25545^2 .

It is a cyclic number.

It is not a de Polignac number, because 1161320161 - 2²³ = 1152931553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1161320191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 482280 + ... + 484681.

It is an arithmetic number, because the mean of its divisors is an integer number (290572081).

Almost surely, 2^1161320161 is an apocalyptic number.

It is an amenable number.

1161320161 is a deficient number, since it is larger than the sum of its proper divisors (968163).

1161320161 is an equidigital number, since it uses as much as digits as its factorization.

1161320161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968162.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 1161320161 is about 34078.1478516659. The cubic root of 1161320161 is about 1051.1160200401.

Adding to 1161320161 its reverse (1610231611), we get a palindrome (2771551772).

The spelling of 1161320161 in words is "one billion, one hundred sixty-one million, three hundred twenty thousand, one hundred sixty-one".